Lubricating oil



Patented Jan. 19, 1943 LUBRICATING OIL Bert E. Lincoln and Gordon D.Byrkit, Ponca City,

Okla., assignors, by mesne assignments, to The Lubri-Zol DevelopmentCorporation, Cleveland,

Ohio, a corporation of Delaware Np Drawing. Application March 9, 1939,Serial No. 2s0,s10

21 Claims. (Cl. 252-58) invention relates to lubricating oil andspecifically to a composition of matter having manydesirablecharacteristics for practical lubrication.

This application is a continuation in part of our co-pending applicationSerial No. 16,410, filed April 15, 1935, now issued as Patent No.2,150,177 of March 14, 1939. x

In the manufacture of lubricating oil designed for use in modernautomotive equipment, the demands on the lubricants have increasedmarkedly in recent years. While the low speed engines designed withBabbitt bearings operating with comparatively large clearances betweenthe journals and bearings and between pistons and cylinders required noexceptional properties in the lubricating oil, the modern high speedengines using harder journals and bearings and operating at much smallerclearances require that the lubricating oil possess a variety of unusuall characteristics in order to lubricate this type of enginesatisfactorily. Among these characteristics are increased stabilitytoward heat and oxidation, reduced tendency to develop sludge andacidity in use, and most important of ali, the ability to carry highloads without permitting metal-to-metal contact. The necessity of theseproperties, particularly that of high film strength in lubricating oils,is emphasized in all the lit-. erature treating of lubrication of modernautomotive equipment. Thus, forexample, in the National Petroleum News,vol. 2'7, #5, page 25 (January 30, 1935), numerous recommendations forthe use of extreme pressure lubricants in -modem automobiles are cited.The use of such addition agents may affect either favorably or adverselysuch other properties of the hydrocarbon oil as stability toward heatand oxidation, corrosiveness after'use', cold test, and other importantproperties. In the design of the addition agent, such other effects mustbe considered, since the hard alloy bearings are very suscep tible tocorrosion, for example, by acids derived from both the addition agentand the hydrocarbon base. Unless very soluble addition agents are used,the cloud-point and cold test oi. the blended oil may be raised. This isa distinct disadvantage, particularly in winter grade oils.

Some addition agents may accelerate oxidation or the oil, while othersmay be without effect or even decrease the susceptibility to oxidationduring use. All of the eflects of the'addition agent on the blend must,therefore, be considered in designing a material for the, improvement ofthe load-cam ability of the oil. It is also an object of this inventionto provide a lubricating composition suitable for use in aviation andDiesel engines.

In the previous art of preparing addition agents for the improvement ofthe film strength of'lubricating oils, little cognizance has been takenof the relation between the molecular structure of the organic moleculeand its effect on the properties of the oil with which it is blended. Wehave discovered that the presence of particular functional groups andtheir position in the organic molecule have a profound efiect upon theability of the material to raise the loadcarrying efliciency of themineral oil with which it is blended. I

We have discovered that the introduction of negative radicals, and moreparticularly of aryl groups such as the phenyl or substittued phenylgroup, into the molecule of a halogenated organic compound serves toactivate the halogen in such a Way that the arylated compound is manytimes more efiective as an extreme pressure compound than the unarylatedcompound. This In view of this, we have used the terms.aryl

and substituted aryl" to include halogenated improvement which arylationeffects in extreme pressure character is not attended by any deleteriouschange in any other properties of the addition agent,'but theintroduction of the aryl group often improves the other properties ofthe essence so that the blended oil may have better stability withrespect to heat and oxidation, better cold test, better color after use,and other desirable characteristics. The presence of halogen in an arylradical will increase its negativity.

radicals. The total halogen in the molecule may be on an aliphaticcarbon or carbons or on an aryl carbon or carbons or locatedon bothkinds of carbon atoms. When conditions of use 're quire that theaddition agent be of a highly stable character, 1. e., relativelychemically inactive except under conditions of extreme pressure ortemperature, it is often desirable that the halo-' gen be attached to abenzenoid ring structure.

We have further ascertained that in a halogenated, arylated' aliphaticcompound designed to be used as an addition agen forlubricating oils andwhere the halogen is on an aliphatic carbon atom, to obtain the mostsatisfactory addition agent, it is generally desirable to. have at leastone aryl nucleus to each aliphatic carbon atom.

Broadly stated, our invention comprises a new lubricating compositioncontaining at least 90% by weight of a mineral lubricating oil or itsequivalent and from an efiective amount to of a halogenated polyarylatedaliphatic compound.

While our emphasis is on the use of chlorine compounds because of theirready availability and cheapness, we do not wish to be limited to thisone halogen, since the other halogens are suited to our purpose. Bromineand iodine are more costly than chlorine, while fluorine is very activechemically.

The halogenated, arylated aliphatic compounds which we contemplatedusing may be prepared by any of the methods known to the art, such asthe Friedel-Crafts reaction or other condensation reactions. They may bepurified by distillation, crystallization or other suitable process. Itis important, however, that these essences be free from any traces ofhydrochloric or other acids, so that such corrosive substances will notbe inadvertently introduced into the blend. These may be removed bywashing the essence with dilute caustic, soda ash solutions or the like.

In order to compare various addition agents, we

of the hydrogen atoms of the alkyl halide have been substituted by arylgroups. It is particularly advantageous in these arylated or moreparticularly, phenylated, alkyl halides to have the phenyl group orgroups attached either to the carbon atom which bears the halogen or tothe next carbon atom. This proximity is desirable in order that theactivating influence of the negative phenyl group be efi'ective. I! thelatter be further removed, its influence decreases rapidly with theincrease in the number of carbon atoms intervening between the phenylgroup and the halogen have made blends consisting of one-half percent orone percent of the added material and 99.5 percent or 99 percent of awell refined mineral or hydrocarbon lubricant of the viscosity of S. A.E. 30. In prac icing our invention, however, the hydrocarbon lubricantof the blend may be any material included in that class named, be itnatural or synthetic in character, and including hydrogenated andvoltolized'oils. These hydrocarbon oils may be of any classificationsince the invention is not limited to oils of the S. A. E.classification.

For the sake of comparison we have used 0.5% and 1% concentrations ofaddition agents in our exemplifying blends. However, it is to beunderstood that in practicing our invention any suitable concentrationof addition agent from 0.2% to 5 or as much as 10% may be used in orderto obtain effects of the desired magnitude.

These blends were then tested by recommended methods on the machinemanufactured for the purpose by the Timken Roller Bearing Company andhereafter referred to as the Timken machine. Its construction andoperation are fully described in the literature of the art.

In order to examine the efiect of introducing various substituents intoorganic molecules so as to increase the film strength of their blends,we have found it helpful to express the eificiency of the halogens, forexample, in the-case of a halogenated addition agent, as a ratio of theTimken film strength in pounds per square inch to the percent ofchlorine present in the addition agent.

Efficiency index: Increase in Percent of chlorine in the additionproduct This ratio, which we have chosen to call the "efliciency index,does not constitute an essential part of our invention. but does serveto make more obvious the effect of diiierences in molecular structurewhich will make our invention clear to those skilled in the art.

' The advantages of our invention become apparent upon examining theeffect of introducing phenyl or other substituted or unsubstitutedaromatic radicals of negative character into various organic molecules.Thus alkyl halides of low molecular weight have a much smaller effect onthe film strength of blends with mineral oil compared with similarcompounds in which part or all film strength (pounds per sq. in.)

atoms.

Aryl groups other than the phenyl group are, of course, entirelysatisfactory and among them may be included the following:

Benzyl Anthracyl Tolyl Phenanthryl Xylyl Xenyl Naphthyl The specificexamples given herein serve to show how we practice our invention, andare not to be considered as limitations on its scope.

1 Note, ethylene chloride and ethylene dichloride are identical.

It is apparent irom this comparison that while the introduction of thefour phenyl groups in the ethylene dichloride increases theeffectiveness of the latter in improving the film strength, it alsoreduces the percentage chlorine content of the molecule so much that inorder to make a fair comparison of the two compounds when employing themin equal amounts it is necessary to take this into account. Theeiilciency index indicates that such halogen as is contained in thephenylated compound is more than nine times as effective in improvingthe load carrying characteristics in the blend.

The blend of tetraphenyi ethylene chloride (dichloride) was as stabletoward oxidation as the hydrocarbon oil from which it was prepared and asatisfactory cold test was obtained.

The effect 01' phenylation is shown here. both in the Timken test and inthe efilciency index, but more strikingly in the latter. While hexylchloride makes but relatively poor use oi its halogen, beta-phenyl ethylchloride produces five times the film strength in spite of its lowerchlorine content. This is shown in the efliciency index which is aboutthirty greater in the cas of the more efiiclent compound.

The high value shown for the blend of triphenyl methyl chlorideillustrates the advantage *Diphenyl dichior methane of having one ormoreof the aryl groups attached to the same carbon bearing the halogen.

This compound is three times as efllcient as betaphenyl ethyl chloride,but beta-phenyl ethyl chloride is much mor efficient than either of thealkyl halides.

All of these blends were satisfactory in other respects, such as coldtest, stability, color, noncorrosiveness, and other properties.

Inasmuch as the compositions of our invention are designed to beemployed where gumming and.

sludge formation would be highly undesirable, as

in the crankcases of internal combustion engines, the lubricant shouldbe substantially free of compounds havingsuch tendencies suchasunsaturated aliphatic compounds and the like which readily oxidizeand/or polymerize to form objectionable materials.

Example III T099 parts of S. A. E. 30 universal oil of high quality, onepart'by weight of benzophenone di- "chloride was'added and the twocomponents thoroughly blended together. A load of 59,000

'pounds per square inch was carried satisfactorily by this blend on theTimken machine,

such composition affecting its use as a lubricant improved byincorporating therein from about 0.2% to about 5% of a halogenatedpolyarylated aliphatic compound having at least a portion of the halogenon such aliphatic group.

' gen on such aliphatic group.

while the unblended oilcarried 6,000 to 7,000 1 pounds per square inchpressure. The efliciency index of this addition agent is 1966.7. 'Allother properties of this blend were satisfactory.

Among the groups contemplated by this in;- vention and illustrated bythe preceding examples are the following structural groups in which Arepresents an'aryl group:

A typical compound containing a group such as that of Group 0 isl-chloro, 2, 3 diphenyl propane.

Other'modes of applying the principle of our invention maybe employedinstead of the one explained, change being made as regardsthecomposition and method herein disclosed, provided the ingredients orsteps stated by any of the following claims or the equivalent of suchstated ingredients or steps be employed.

W therefore particularly point out and distinctly "claim as ourinvention:

1. A lubricating composition containing as a principal lubricatingconstituent at least 90% mineral lubricating oil with the properties ofsuch composition affecting its use as a lubricant improved byincorporating therein a minor amount of a halogenated polyarylatedaliphatic compound having at least a portion of the halogen on suchaliphatic group. i

2. A lubricating composition containing'as a principal lubricatingconstituent at least 90% mineral lubricating oilv with the properties ofsuch composition afiectingits use as a lubricant improved byincorporating therein from about 0.2% to about 10% of a halogenatedpolyarylated aliphatic compound having at least a portion of the halogenon such aliphatic group.

3. A lubricating compositioncontaining as a principal lubricatingconstituent at least 90% mineral lubricating oil with the properties of5. A lubricating composition containing as a principal lubricatingconstituent at least 90% mineral lubricating oil with the properties ofsuch composition affecting its use as a lubricant improved byincorporating therein from about 0.2% toabout 10% ofa chlorinatedpolyarylated aliphatic compound having at least a portion of the halogenon such aliphatic group.

6. A lubricating composition containing as a principal lubricatingconstituent at least 90% mineral lubricating 'oil with the properties ofsuch composition affecting its use as a lubricant improved byincorporating therein from about 0.2% to about 5% of a chlorinatedpoiyarylated aliphatic compound having at least a portion of the halogenon such aliphatic group.

7. A lubricating composition containing as a principal lubricatingconstituent at least 90% v mineral lubricating oil with theproperties ofsuch composition affecting its use as a lubricant improved byincorporating therein a minor amount of a halogenated polyarylatedaliphatic compound in which at least a. portion of the halogen isattached to a benzenoid ring structure.

8. A lubricating. composition containing as a principal lubricatingconstituent at least mineral lubricating oil with the properties of suchcomposition affecting its use as a lubricant improved by incorporatingtherein a minor 'amount of a'halogenated polyarylated aliphatic compoundin which the halogen is attached to the aliphatic nucleus adjacent to anaryl group.

9. A lubricating composition containing as a principal lubricatingconstituent at least 90% mineral lubricating oil with the properties ofsuch composition aflecting its use as a lubricant improved byincorporating therein from about 0.2% to about 10% of a chlorinatedpolyphenylated aliphatic compound.

10. A lubricating oil-comprising in combination a major'amount ofhydrocarbon oil'and a minor amount of an oil soluble, arylated,chlorinated aliphatic hydrocarbon containing the following structure:

in which A represents an aryl group. I

11. A lubricating oil comprising in combination a magioramount ofhydrocarbon oil and a minor amount of an oil soluble, arylated,chlorinated, aliphatic hydrocarbon containing the following structure: i

in which A represents an aryl group.

genated aliphatic hydrocarbon containing the following structure:

l l ...C C. i t,

in which A represents an aryl group.

13. A lubricating oil comprising in combination a major amount ofhydrocarbon oil and'a minor amount of an oil soluble, arylated,halogenated aliphatic hydrocarbon containing the following structure:

in which A represents an aryl group.

14. A lubricating composition containing as a principal lubricatingconstituent at least 90% mineral lubricating oil with the properties ofsuch composition affecting its use as a lubricant improved byincorporating therein a minor amount of a halogenated polyarylatedaliphatic hydrocarbon having at least a portion of the halogen on suchaliphatic group.

15. A lubricating composition containing as a principal lubricatingconstituent at least 90% mineral lubricating oil with the properties ofsuch composition aflecting its use as a lubricant improved byincorporating therein from about 0.2% to about 10% of a halogenatedpolyarylated aliphatic hydrocarbon having at least a portion of thehalogen on such. aliphatic group.

16. A lubricating composition containing as a principal lubricatingconstituent at least 90% mineral lubricating oil with the properties ofsuch composition affecting its use as a lubricant improved byincorporating therein a minor amount of diphenyl dichlor methane.

17. A lubricating composition comprising a mineral lubricating oil and asmall amount of a halogenated polyarylalkyl in which halogen is attachedto the alkyl group. v

18. A lubricating composition comprising a mineral lubricating oil and asmall amount of a chlorinated polyarylalkyl in which halogen is attachedto the alkyl group.

